Table 1.
Implemented carbon turnover processes in investigated GVMs (modified from Friend et al. 2014 and McDowell et al. 2011)
| Model | Carbon turnover processes | |||||
|---|---|---|---|---|---|---|
| Background rated | Competition | Fire | Growth efficiency, NPP or carbon balance dependence | Heat stress | Phenology affected by climate | |
| HYBRID4 c , e | +a | Forest gap model; competition for light, water and N; controls mortality of individuals due to the carbon balance of the tree (see on the right) | ‐b | Mortality of individual trees if insufficient C available in foliage + storage C or fine root + storage C; effects of drought‐induced embolism and frost damage on carbon uptake | ‐b | Phenology of dry‐ and cold‐deciduous trees is affected by drought and frost |
| JeDi c , f | Turnover times are affected by functional trait parameters | Abundances of different plant growth strategies determined from their biomass | ‐b | Increased leaf and fine root turnover if current NPP < 0 and long‐term NPP < 0 | ‐b | Phenology affected by plant strategy and climate |
| JULES c , g | Division into disturbance and turnover rate | Density dependent competition for light | ‐b | ‐b | ‐b | Leaf turnover increases in case of low temperatures |
| LPJml c , h | +a | Competition for light and water (canopy cover upper threshold) | f(Fuel load, litter moisture) (Thonicke et al., 2001) | Growth efficiency dependent mortality = f(Biomass increment/Leaf area) | f(Annual growing degree‐days (GDD) above a PFT‐specific threshold); linear; only in boreal forests | In dependence of GDD and frost for deciduous trees |
| ORCHIDEE i | PFT‐specific background rate (including rate lost due to herbivory; fraction of leaves and fine roots lost dependent on leaf age) | ‐b | ‐b | ‐b | ‐b | Leaf longevity is reduced in case of soil moisture stress, atmospheric dryness, and very high temperatures |
| SDGVM j | Maximum age and fixed rate | Thinning as a result of competition between cohorts within each individual PFT | f(Monthly averages of precipitation and temperature) | Mortality of cohort if storage C depleted; mortality = 1 for annual NPP < 10 g m−2 yr−1 which decreases up to 0 for NPP ≥600 g m−2 yr−1 | ‐b | ‐b |
| VISIT k | +a | ‐b | f(Fuel load, litter moisture) (Thonicke et al., 2001) | ‐b | ‐b | ‐b |
a
Implemented mortality algorithm.
b
Mortality algorithm not implemented.
c
DGVM: Mortality of PFTs occurs, for example, if long‐term climate exceeds climatic tolerances (LPJml).
d
Background mortality rate usually divided between foliage, wood, and fine root turnover rates.
f
Pavlick et al. (2013).
g
Clark et al. (2011).
h
Sitch et al. (2003).
j
Woodward and Lomas (2004).